fuel leak
Thread Starter
Instructor
Joined: Nov 2011
Posts: 105
Likes: 0
fuel leak
recently bought a 79 vette with 383 and have been chasing a gas smell, and i found it but only because its a fuel leak that only occurs when the car has been running for a minute or two. i cant pin down where it is comming from, its under the center of the rear bumber, i looked under and the center part of the gas tank is wet from the leak but it seems to come from above it somewhere. i can see up to the gas cap from underneath and it isnt wet. i cant figure it out, previous owner suggested the fuel overflow return line from top of tank. anyone got a diagram of this so i know where to be looking and instructions on how to drop the tank if i need to? also its not a strong leak it drips and theres one drop approx every 5 to ten seconds, and once the car is off it stops leaking a few seconds afterwards
Last edited by usnfenix; Dec 1, 2011 at 08:19 PM.
Racer
Joined: Feb 2011
Posts: 384
Likes: 0
From: Northern New Jersey
You will need to drop the tank. Here's a diagram of fuel lines.
http://www.mamotorworks.com/corvette...431-10197.html
http://www.mamotorworks.com/corvette...431-10197.html
Race Director
Joined: May 2006
Posts: 18,626
Likes: 2,553
well for what it worth the older years, 1969, have a cork gasket between the neck and the tank body. This deteriorates over the years and when the tank is close to full it will leak. Try to see thru the gas filler door if there are maybe 12 small screws holding the neck to the body of the tank.
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Thread Starter
Instructor
Joined: Nov 2011
Posts: 105
Likes: 0
ok lets see if these pics will work. first one is before car is running and has been sitting out all night. second and third are after running for ten min. note how the wires are also soaked.
the view and angle of the photos is right underneath the car looking up towards the underside of the gas cap
the view and angle of the photos is right underneath the car looking up towards the underside of the gas cap
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
There is a 1/4 in. hose up there that is on the fuel return line. It is under slight pressure. The 3/8 supply line is under suction when running but can still leak. I replaced my hoses on my '77 last year and they were just about to split at the rubber to steel line connection. The steel line has a slight flare/bulge that streches hose slightly and this is where the rubber can fail. If yours have never been replaced they are a good bet to be the cause of the leak. mike...
